The system provides a practical method for measuring how the spirit travels when people speak or sing.
A new method for visualizing breathing that is exhaled while someone is talking or singing can provide important new insights into how diseases like e.g. Covida-19 spread and effectiveness of face masks.
“Scientists believe in SARS-COV-2 the virus is spread mainly through airborne droplets that can be transmitted through breathing or expelled through coughing or sneezing, ”said Thomas Moore of Rollins College, who conducted the research. “But it is also transmitted by air aerosols, which are small particles that stay in the air longer than larger droplets. The system I developed provides a way to estimate how far the breath travels before it is dispersed in the surrounding air and can provide visual evidence that the masks significantly limit the distance the breath travels in the air. “
In the journal Optical Society (OSA) applies optics, Moore describes how he used a variation of the point model electron interferometry to distinguish the image temperature between the breathing pattern and the surrounding air. The new technique can also be used to study the details of how the breath flows from the mouth while speaking or singing, which can be useful for music instruction and speech therapy.
The new imaging technique was used to image a professional musician playing a flute. The video shows that a plug-in available on the market can effectively redirect the flow of air from the flute. This is a demonstration of the published imaging technique that is being further investigated. The image shows only the temperature change associated with respiratory distress, which does not necessarily reflect the movement of viral particles involved in respiration. Credit: Thomas Moore, Rollins College
From musical instruments to people
Moore originally developed imaging technology to study the flow of air through musical instruments such as organ tubes. “In response to the COVID-19 pandemic, I started imagining the spirit of people talking and singing,” he said. “I realized that by scaling up my existing system, it could likely determine how long the breathing lasts and how effective the masks can be in limiting the rate of respiration.”
Most existing approaches used to image inspired breathing require expensive equipment and can only image a relatively small area. Moore designed a system that uses commonly available commercially available optical components to overcome these limitations.
“I used an electronic interferometry variant of the point model, which has been used for many years to study the vibrating patterns of solid objects,” Moore said. “The innovation was to change the system in such a way that it could be used to image transparent things, such as breathing, instead of strong vibrating objects.”
The imaging system uses the fact that the speed of light will vary depending on the temperature of the air through which it passes. Because the breath is warmer than the surrounding air, the light transmitted through the breath reaches the camera a little faster than the light that did not pass through it. This small change in the speed of light can be used to create breathing images.
Moore tested the new system by imagining the breathing of two professional vocalists singing and a professional musician playing a flute, one of the few instruments where the musician blows directly into the surrounding air. “Working with musicians immediately confirmed that the system worked well and could be used to study a variety of problems,” he said.
Changing the air flow
Moore is currently using the method to study how effective the masks are in reducing the distance traversed by breathing aerosols. He is particularly interested in studying singing because research shows that more aerosol is released when he sings or speaks aloud than when he speaks normally. He is also working to make the system more vibration resistant and to further increase the size of the system to image larger areas.
Moore says the technique has already uncovered new information that could affect how we approach distancing and camouflage requests, especially when we are outside. He expects to present these results for publication soon.
“The pandemic has caused an economic disaster for many musicians and any information we can give them that will help them get back to work is important,” Moore said. “We have had a lot of interest from the music community and I expect the healthcare community to be interested as well once we start publishing our results.”
Reference: “Visualization of breathing inspired by the interferometry of the electronic model of transmission points” by Thomas R. Moore, 21 December 2020, applies optics.
DOI: 10.1364 / AO.410784